Here’s why they call male bighorn sheep rams. During the mating season or “rut” in November and December, the rams butt heads while sparring for females. The massive impacts can break horns and sends a cracking noise echoing through the mountains. It’s an incredible natural event to witness. Photo from the National Elk Refuge in Wyoming by Adam Jewell. Posted on Tumblr by the US Department of the Interior, 5/18/17.